Many of the monthly biomass fraction values are too low and seem to reflect phenological activity/% live than what they were originally intended for - to represent the monthly fraction of annual aboveground biomass (live & dead) for each functional type.
For example, for sagebrush, most of the biomass (i.e. wood) stays attached to the plant year round. A small fraction of aboveground biomass is lost each year as ephermal leaves are dropped and become litter. This issue will re-evaluate the default biomass fraction values and adjust them upwards when necessary. In addition, we currently only have one month where biomass fraction = 1.0. Having at least one month where biomass fractions = 1.0 is critical for SOILWAT2 to simulate the biomass that was simulated in STEPPE in the previous year. However, it is completely responsible to expect that there may be more than one month where biomass fraction is at 1.0 and this issue will make those adjustments as well.
The spreadsheet below contains the old biomass fractions and a proposal for new biomass fractions. It is important to remember that these fractions represent the fraction of total aboveground biomass that occurs in a given month for a given functional group. This include dead and living biomass. When biomass fractions are below 1.0, that indicates that some biomass has been lost as litter during in that month. Biomass fractions are multiplied by total annual biomass for each STEPPE functional group, then biomass is accumulated for all STEPPE functional groups that belong to each SOILWAT2 vegetation type, and then used as input for SOILWAT2.
In almost all months for all functional groups, I believe we were formerly underestimating biomass fractions. My new proposed values may need to be adjusted downward a bit for some groups - see the comments column for some questions I have for the group.
kpalmqui
commented
4 years ago
Identical to https://github.com/DrylandEcology/STEPWAT2/issues/451 in STEPWAT2.
Many of the monthly biomass fraction values are too low and seem to reflect phenological activity/% live than what they were originally intended for - to represent the monthly fraction of annual aboveground biomass (live & dead) for each functional type.
For example, for sagebrush, most of the biomass (i.e. wood) stays attached to the plant year round. A small fraction of aboveground biomass is lost each year as ephermal leaves are dropped and become litter. This issue will re-evaluate the default biomass fraction values and adjust them upwards when necessary. In addition, we currently only have one month where biomass fraction = 1.0. Having at least one month where biomass fractions = 1.0 is critical for SOILWAT2 to simulate the biomass that was simulated in STEPPE in the previous year. However, it is completely responsible to expect that there may be more than one month where biomass fraction is at 1.0 and this issue will make those adjustments as well.
The spreadsheet below contains the old biomass fractions and a proposal for new biomass fractions. It is important to remember that these fractions represent the fraction of total aboveground biomass that occurs in a given month for a given functional group. This include dead and living biomass. When biomass fractions are below 1.0, that indicates that some biomass has been lost as litter during in that month. Biomass fractions are multiplied by total annual biomass for each STEPPE functional group, then biomass is accumulated for all STEPPE functional groups that belong to each SOILWAT2 vegetation type, and then used as input for SOILWAT2.
In almost all months for all functional groups, I believe we were formerly underestimating biomass fractions. My new proposed values may need to be adjusted downward a bit for some groups - see the comments column for some questions I have for the group.
biomass.fractions.xlsx
I will be getting Bill and John's feedback on these values, along with @dschlaep when he returns from his trip.